1 /* 2 * AD7879-1/AD7889-1 touchscreen (I2C bus) 3 * 4 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc. 5 * 6 * Licensed under the GPL-2 or later. 7 */ 8 9 #include <linux/input.h> /* BUS_I2C */ 10 #include <linux/i2c.h> 11 #include <linux/module.h> 12 #include <linux/types.h> 13 #include <linux/of.h> 14 #include <linux/pm.h> 15 16 #include "ad7879.h" 17 18 #define AD7879_DEVID 0x79 /* AD7879-1/AD7889-1 */ 19 20 /* All registers are word-sized. 21 * AD7879 uses a high-byte first convention. 22 */ 23 static int ad7879_i2c_read(struct device *dev, u8 reg) 24 { 25 struct i2c_client *client = to_i2c_client(dev); 26 27 return i2c_smbus_read_word_swapped(client, reg); 28 } 29 30 static int ad7879_i2c_multi_read(struct device *dev, 31 u8 first_reg, u8 count, u16 *buf) 32 { 33 struct i2c_client *client = to_i2c_client(dev); 34 u8 idx; 35 36 i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf); 37 38 for (idx = 0; idx < count; ++idx) 39 buf[idx] = swab16(buf[idx]); 40 41 return 0; 42 } 43 44 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val) 45 { 46 struct i2c_client *client = to_i2c_client(dev); 47 48 return i2c_smbus_write_word_swapped(client, reg, val); 49 } 50 51 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = { 52 .bustype = BUS_I2C, 53 .read = ad7879_i2c_read, 54 .multi_read = ad7879_i2c_multi_read, 55 .write = ad7879_i2c_write, 56 }; 57 58 static int ad7879_i2c_probe(struct i2c_client *client, 59 const struct i2c_device_id *id) 60 { 61 struct ad7879 *ts; 62 63 if (!i2c_check_functionality(client->adapter, 64 I2C_FUNC_SMBUS_WORD_DATA)) { 65 dev_err(&client->dev, "SMBUS Word Data not Supported\n"); 66 return -EIO; 67 } 68 69 ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq, 70 &ad7879_i2c_bus_ops); 71 if (IS_ERR(ts)) 72 return PTR_ERR(ts); 73 74 i2c_set_clientdata(client, ts); 75 76 return 0; 77 } 78 79 static int ad7879_i2c_remove(struct i2c_client *client) 80 { 81 struct ad7879 *ts = i2c_get_clientdata(client); 82 83 ad7879_remove(ts); 84 85 return 0; 86 } 87 88 static const struct i2c_device_id ad7879_id[] = { 89 { "ad7879", 0 }, 90 { "ad7889", 0 }, 91 { } 92 }; 93 MODULE_DEVICE_TABLE(i2c, ad7879_id); 94 95 #ifdef CONFIG_OF 96 static const struct of_device_id ad7879_i2c_dt_ids[] = { 97 { .compatible = "adi,ad7879-1", }, 98 { } 99 }; 100 MODULE_DEVICE_TABLE(of, ad7879_i2c_dt_ids); 101 #endif 102 103 static struct i2c_driver ad7879_i2c_driver = { 104 .driver = { 105 .name = "ad7879", 106 .pm = &ad7879_pm_ops, 107 .of_match_table = of_match_ptr(ad7879_i2c_dt_ids), 108 }, 109 .probe = ad7879_i2c_probe, 110 .remove = ad7879_i2c_remove, 111 .id_table = ad7879_id, 112 }; 113 114 module_i2c_driver(ad7879_i2c_driver); 115 116 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 117 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver"); 118 MODULE_LICENSE("GPL"); 119